Annually in the United States, millions of children experience trauma such as exposure to neighborhood violence or experiencing abuse. These events increase risk for post-traumatic stress, and thereby a variety of poor health outcomes including depression, sleep disturbances, obesity, and substance use. Although many childhood traumatic stress screeners exist, current tools often do not screen for protective factors that child service providers can leverage to reduce a child's traumatic stress symptoms. Without identifying protective factors for children who screen positive, individuals conducting screening are not adequately equipped to address trauma symptoms, and in turn, children who exhibit symptoms may experience added stress and anxiety. Thus, although childhood trauma is prevalent, traumatic stress is often undetected and untreated. The status quo is to refer children with traumatic stress to mental health professionals, but child mental health service need far outstrips capacity. This supply-demand imbalance necessitates the identification of protective factors for reducing traumatic stress symptoms that can be assessed and addressed in non-psychiatry settings. The present research aims to move childhood trauma screening forward by exploring the utility of adding social support indicators to a traumatic stress screener. Specifically, the research will identify if and when social support can reduce traumatic stress symptoms among children who have experienced early life trauma. This theory-informed study will use longitudinal data from 2,065 children with Child Protective Services contact from the National Survey of Child and Adolescent Well-Being (NSCAW), and it will apply structural equation modeling (SEM) and latent growth modeling (LGM). It will first identify whether social support from peers reduces a child's post-traumatic stress symptoms, both in conjunction with?and above and beyond? mental health services (Aim 1). Because a characteristic change in adolescence is the movement towards independence combined with an increasing reliance on friends, peer social support may become more critical to reducing traumatic stress symptoms as children age into. Therefore, this study will also identify ages when peer social support most effectively reduces traumatic stress symptoms among youth (Aim 2). Results will determine the utility of adding social support indicators to trauma screening, and in turn, will have the potential to inform developmentally appropriate interventions for reducing post-traumatic stress symptoms in youth. Through (1) a research project that focuses on how to improve existing traumatic stress screeners, accompanied by (2) a training plan that enhances the applicant's research method and interpretation skills, research communication abilities, knowledge of the services provided to children with traumatic experiences, and understanding of child welfare policy, this fellowship will lay the groundwork for a research career as an independent developmental scientist with a focus on translating research into knowledge, tools, and resources for child service providers who work with children who have experienced early life adversity.